xref: /openbmc/qemu/hw/i386/vapic.c (revision 9dbab31d)
1  /*
2   * TPR optimization for 32-bit Windows guests (XP and Server 2003)
3   *
4   * Copyright (C) 2007-2008 Qumranet Technologies
5   * Copyright (C) 2012      Jan Kiszka, Siemens AG
6   *
7   * This work is licensed under the terms of the GNU GPL version 2, or
8   * (at your option) any later version. See the COPYING file in the
9   * top-level directory.
10   */
11  
12  #include "qemu/osdep.h"
13  #include "qemu/module.h"
14  #include "sysemu/sysemu.h"
15  #include "sysemu/cpus.h"
16  #include "sysemu/hw_accel.h"
17  #include "sysemu/kvm.h"
18  #include "sysemu/runstate.h"
19  #include "exec/address-spaces.h"
20  #include "hw/i386/apic_internal.h"
21  #include "hw/sysbus.h"
22  #include "hw/boards.h"
23  #include "migration/vmstate.h"
24  #include "qom/object.h"
25  
26  #define VAPIC_IO_PORT           0x7e
27  
28  #define VAPIC_CPU_SHIFT         7
29  
30  #define ROM_BLOCK_SIZE          512
31  #define ROM_BLOCK_MASK          (~(ROM_BLOCK_SIZE - 1))
32  
33  typedef enum VAPICMode {
34      VAPIC_INACTIVE = 0,
35      VAPIC_ACTIVE   = 1,
36      VAPIC_STANDBY  = 2,
37  } VAPICMode;
38  
39  typedef struct VAPICHandlers {
40      uint32_t set_tpr;
41      uint32_t set_tpr_eax;
42      uint32_t get_tpr[8];
43      uint32_t get_tpr_stack;
44  } QEMU_PACKED VAPICHandlers;
45  
46  typedef struct GuestROMState {
47      char signature[8];
48      uint32_t vaddr;
49      uint32_t fixup_start;
50      uint32_t fixup_end;
51      uint32_t vapic_vaddr;
52      uint32_t vapic_size;
53      uint32_t vcpu_shift;
54      uint32_t real_tpr_addr;
55      VAPICHandlers up;
56      VAPICHandlers mp;
57  } QEMU_PACKED GuestROMState;
58  
59  struct VAPICROMState {
60      SysBusDevice busdev;
61  
62      MemoryRegion io;
63      MemoryRegion rom;
64      uint32_t state;
65      uint32_t rom_state_paddr;
66      uint32_t rom_state_vaddr;
67      uint32_t vapic_paddr;
68      uint32_t real_tpr_addr;
69      GuestROMState rom_state;
70      size_t rom_size;
71      bool rom_mapped_writable;
72      VMChangeStateEntry *vmsentry;
73  };
74  
75  #define TYPE_VAPIC "kvmvapic"
76  OBJECT_DECLARE_SIMPLE_TYPE(VAPICROMState, VAPIC)
77  
78  #define TPR_INSTR_ABS_MODRM             0x1
79  #define TPR_INSTR_MATCH_MODRM_REG       0x2
80  
81  typedef struct TPRInstruction {
82      uint8_t opcode;
83      uint8_t modrm_reg;
84      unsigned int flags;
85      TPRAccess access;
86      size_t length;
87      off_t addr_offset;
88  } TPRInstruction;
89  
90  /* must be sorted by length, shortest first */
91  static const TPRInstruction tpr_instr[] = {
92      { /* mov abs to eax */
93          .opcode = 0xa1,
94          .access = TPR_ACCESS_READ,
95          .length = 5,
96          .addr_offset = 1,
97      },
98      { /* mov eax to abs */
99          .opcode = 0xa3,
100          .access = TPR_ACCESS_WRITE,
101          .length = 5,
102          .addr_offset = 1,
103      },
104      { /* mov r32 to r/m32 */
105          .opcode = 0x89,
106          .flags = TPR_INSTR_ABS_MODRM,
107          .access = TPR_ACCESS_WRITE,
108          .length = 6,
109          .addr_offset = 2,
110      },
111      { /* mov r/m32 to r32 */
112          .opcode = 0x8b,
113          .flags = TPR_INSTR_ABS_MODRM,
114          .access = TPR_ACCESS_READ,
115          .length = 6,
116          .addr_offset = 2,
117      },
118      { /* push r/m32 */
119          .opcode = 0xff,
120          .modrm_reg = 6,
121          .flags = TPR_INSTR_ABS_MODRM | TPR_INSTR_MATCH_MODRM_REG,
122          .access = TPR_ACCESS_READ,
123          .length = 6,
124          .addr_offset = 2,
125      },
126      { /* mov imm32, r/m32 (c7/0) */
127          .opcode = 0xc7,
128          .modrm_reg = 0,
129          .flags = TPR_INSTR_ABS_MODRM | TPR_INSTR_MATCH_MODRM_REG,
130          .access = TPR_ACCESS_WRITE,
131          .length = 10,
132          .addr_offset = 2,
133      },
134  };
135  
136  static void read_guest_rom_state(VAPICROMState *s)
137  {
138      cpu_physical_memory_read(s->rom_state_paddr, &s->rom_state,
139                               sizeof(GuestROMState));
140  }
141  
142  static void write_guest_rom_state(VAPICROMState *s)
143  {
144      cpu_physical_memory_write(s->rom_state_paddr, &s->rom_state,
145                                sizeof(GuestROMState));
146  }
147  
148  static void update_guest_rom_state(VAPICROMState *s)
149  {
150      read_guest_rom_state(s);
151  
152      s->rom_state.real_tpr_addr = cpu_to_le32(s->real_tpr_addr);
153      s->rom_state.vcpu_shift = cpu_to_le32(VAPIC_CPU_SHIFT);
154  
155      write_guest_rom_state(s);
156  }
157  
158  static int find_real_tpr_addr(VAPICROMState *s, CPUX86State *env)
159  {
160      CPUState *cs = env_cpu(env);
161      hwaddr paddr;
162      target_ulong addr;
163  
164      if (s->state == VAPIC_ACTIVE) {
165          return 0;
166      }
167      /*
168       * If there is no prior TPR access instruction we could analyze (which is
169       * the case after resume from hibernation), we need to scan the possible
170       * virtual address space for the APIC mapping.
171       */
172      for (addr = 0xfffff000; addr >= 0x80000000; addr -= TARGET_PAGE_SIZE) {
173          paddr = cpu_get_phys_page_debug(cs, addr);
174          if (paddr != APIC_DEFAULT_ADDRESS) {
175              continue;
176          }
177          s->real_tpr_addr = addr + 0x80;
178          update_guest_rom_state(s);
179          return 0;
180      }
181      return -1;
182  }
183  
184  static uint8_t modrm_reg(uint8_t modrm)
185  {
186      return (modrm >> 3) & 7;
187  }
188  
189  static bool is_abs_modrm(uint8_t modrm)
190  {
191      return (modrm & 0xc7) == 0x05;
192  }
193  
194  static bool opcode_matches(uint8_t *opcode, const TPRInstruction *instr)
195  {
196      return opcode[0] == instr->opcode &&
197          (!(instr->flags & TPR_INSTR_ABS_MODRM) || is_abs_modrm(opcode[1])) &&
198          (!(instr->flags & TPR_INSTR_MATCH_MODRM_REG) ||
199           modrm_reg(opcode[1]) == instr->modrm_reg);
200  }
201  
202  static int evaluate_tpr_instruction(VAPICROMState *s, X86CPU *cpu,
203                                      target_ulong *pip, TPRAccess access)
204  {
205      CPUState *cs = CPU(cpu);
206      const TPRInstruction *instr;
207      target_ulong ip = *pip;
208      uint8_t opcode[2];
209      uint32_t real_tpr_addr;
210      int i;
211  
212      if ((ip & 0xf0000000ULL) != 0x80000000ULL &&
213          (ip & 0xf0000000ULL) != 0xe0000000ULL) {
214          return -1;
215      }
216  
217      /*
218       * Early Windows 2003 SMP initialization contains a
219       *
220       *   mov imm32, r/m32
221       *
222       * instruction that is patched by TPR optimization. The problem is that
223       * RSP, used by the patched instruction, is zero, so the guest gets a
224       * double fault and dies.
225       */
226      if (cpu->env.regs[R_ESP] == 0) {
227          return -1;
228      }
229  
230      if (kvm_enabled() && !kvm_irqchip_in_kernel()) {
231          /*
232           * KVM without kernel-based TPR access reporting will pass an IP that
233           * points after the accessing instruction. So we need to look backward
234           * to find the reason.
235           */
236          for (i = 0; i < ARRAY_SIZE(tpr_instr); i++) {
237              instr = &tpr_instr[i];
238              if (instr->access != access) {
239                  continue;
240              }
241              if (cpu_memory_rw_debug(cs, ip - instr->length, opcode,
242                                      sizeof(opcode), 0) < 0) {
243                  return -1;
244              }
245              if (opcode_matches(opcode, instr)) {
246                  ip -= instr->length;
247                  goto instruction_ok;
248              }
249          }
250          return -1;
251      } else {
252          if (cpu_memory_rw_debug(cs, ip, opcode, sizeof(opcode), 0) < 0) {
253              return -1;
254          }
255          for (i = 0; i < ARRAY_SIZE(tpr_instr); i++) {
256              instr = &tpr_instr[i];
257              if (opcode_matches(opcode, instr)) {
258                  goto instruction_ok;
259              }
260          }
261          return -1;
262      }
263  
264  instruction_ok:
265      /*
266       * Grab the virtual TPR address from the instruction
267       * and update the cached values.
268       */
269      if (cpu_memory_rw_debug(cs, ip + instr->addr_offset,
270                              (void *)&real_tpr_addr,
271                              sizeof(real_tpr_addr), 0) < 0) {
272          return -1;
273      }
274      real_tpr_addr = le32_to_cpu(real_tpr_addr);
275      if ((real_tpr_addr & 0xfff) != 0x80) {
276          return -1;
277      }
278      s->real_tpr_addr = real_tpr_addr;
279      update_guest_rom_state(s);
280  
281      *pip = ip;
282      return 0;
283  }
284  
285  static int update_rom_mapping(VAPICROMState *s, CPUX86State *env, target_ulong ip)
286  {
287      CPUState *cs = env_cpu(env);
288      hwaddr paddr;
289      uint32_t rom_state_vaddr;
290      uint32_t pos, patch, offset;
291  
292      /* nothing to do if already activated */
293      if (s->state == VAPIC_ACTIVE) {
294          return 0;
295      }
296  
297      /* bail out if ROM init code was not executed (missing ROM?) */
298      if (s->state == VAPIC_INACTIVE) {
299          return -1;
300      }
301  
302      /* find out virtual address of the ROM */
303      rom_state_vaddr = s->rom_state_paddr + (ip & 0xf0000000);
304      paddr = cpu_get_phys_page_debug(cs, rom_state_vaddr);
305      if (paddr == -1) {
306          return -1;
307      }
308      paddr += rom_state_vaddr & ~TARGET_PAGE_MASK;
309      if (paddr != s->rom_state_paddr) {
310          return -1;
311      }
312      read_guest_rom_state(s);
313      if (memcmp(s->rom_state.signature, "kvm aPiC", 8) != 0) {
314          return -1;
315      }
316      s->rom_state_vaddr = rom_state_vaddr;
317  
318      /* fixup addresses in ROM if needed */
319      if (rom_state_vaddr == le32_to_cpu(s->rom_state.vaddr)) {
320          return 0;
321      }
322      for (pos = le32_to_cpu(s->rom_state.fixup_start);
323           pos < le32_to_cpu(s->rom_state.fixup_end);
324           pos += 4) {
325          cpu_physical_memory_read(paddr + pos - s->rom_state.vaddr,
326                                   &offset, sizeof(offset));
327          offset = le32_to_cpu(offset);
328          cpu_physical_memory_read(paddr + offset, &patch, sizeof(patch));
329          patch = le32_to_cpu(patch);
330          patch += rom_state_vaddr - le32_to_cpu(s->rom_state.vaddr);
331          patch = cpu_to_le32(patch);
332          cpu_physical_memory_write(paddr + offset, &patch, sizeof(patch));
333      }
334      read_guest_rom_state(s);
335      s->vapic_paddr = paddr + le32_to_cpu(s->rom_state.vapic_vaddr) -
336          le32_to_cpu(s->rom_state.vaddr);
337  
338      return 0;
339  }
340  
341  /*
342   * Tries to read the unique processor number from the Kernel Processor Control
343   * Region (KPCR) of 32-bit Windows XP and Server 2003. Returns -1 if the KPCR
344   * cannot be accessed or is considered invalid. This also ensures that we are
345   * not patching the wrong guest.
346   */
347  static int get_kpcr_number(X86CPU *cpu)
348  {
349      CPUX86State *env = &cpu->env;
350      struct kpcr {
351          uint8_t  fill1[0x1c];
352          uint32_t self;
353          uint8_t  fill2[0x31];
354          uint8_t  number;
355      } QEMU_PACKED kpcr;
356  
357      if (cpu_memory_rw_debug(CPU(cpu), env->segs[R_FS].base,
358                              (void *)&kpcr, sizeof(kpcr), 0) < 0 ||
359          kpcr.self != env->segs[R_FS].base) {
360          return -1;
361      }
362      return kpcr.number;
363  }
364  
365  static int vapic_enable(VAPICROMState *s, X86CPU *cpu)
366  {
367      int cpu_number = get_kpcr_number(cpu);
368      hwaddr vapic_paddr;
369      static const uint8_t enabled = 1;
370  
371      if (cpu_number < 0) {
372          return -1;
373      }
374      vapic_paddr = s->vapic_paddr +
375          (((hwaddr)cpu_number) << VAPIC_CPU_SHIFT);
376      cpu_physical_memory_write(vapic_paddr + offsetof(VAPICState, enabled),
377                                &enabled, sizeof(enabled));
378      apic_enable_vapic(cpu->apic_state, vapic_paddr);
379  
380      s->state = VAPIC_ACTIVE;
381  
382      return 0;
383  }
384  
385  static void patch_byte(X86CPU *cpu, target_ulong addr, uint8_t byte)
386  {
387      cpu_memory_rw_debug(CPU(cpu), addr, &byte, 1, 1);
388  }
389  
390  static void patch_call(X86CPU *cpu, target_ulong ip, uint32_t target)
391  {
392      uint32_t offset;
393  
394      offset = cpu_to_le32(target - ip - 5);
395      patch_byte(cpu, ip, 0xe8); /* call near */
396      cpu_memory_rw_debug(CPU(cpu), ip + 1, (void *)&offset, sizeof(offset), 1);
397  }
398  
399  typedef struct PatchInfo {
400      VAPICHandlers *handler;
401      target_ulong ip;
402  } PatchInfo;
403  
404  static void do_patch_instruction(CPUState *cs, run_on_cpu_data data)
405  {
406      X86CPU *x86_cpu = X86_CPU(cs);
407      PatchInfo *info = (PatchInfo *) data.host_ptr;
408      VAPICHandlers *handlers = info->handler;
409      target_ulong ip = info->ip;
410      uint8_t opcode[2];
411      uint32_t imm32 = 0;
412  
413      cpu_memory_rw_debug(cs, ip, opcode, sizeof(opcode), 0);
414  
415      switch (opcode[0]) {
416      case 0x89: /* mov r32 to r/m32 */
417          patch_byte(x86_cpu, ip, 0x50 + modrm_reg(opcode[1]));  /* push reg */
418          patch_call(x86_cpu, ip + 1, handlers->set_tpr);
419          break;
420      case 0x8b: /* mov r/m32 to r32 */
421          patch_byte(x86_cpu, ip, 0x90);
422          patch_call(x86_cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]);
423          break;
424      case 0xa1: /* mov abs to eax */
425          patch_call(x86_cpu, ip, handlers->get_tpr[0]);
426          break;
427      case 0xa3: /* mov eax to abs */
428          patch_call(x86_cpu, ip, handlers->set_tpr_eax);
429          break;
430      case 0xc7: /* mov imm32, r/m32 (c7/0) */
431          patch_byte(x86_cpu, ip, 0x68);  /* push imm32 */
432          cpu_memory_rw_debug(cs, ip + 6, (void *)&imm32, sizeof(imm32), 0);
433          cpu_memory_rw_debug(cs, ip + 1, (void *)&imm32, sizeof(imm32), 1);
434          patch_call(x86_cpu, ip + 5, handlers->set_tpr);
435          break;
436      case 0xff: /* push r/m32 */
437          patch_byte(x86_cpu, ip, 0x50); /* push eax */
438          patch_call(x86_cpu, ip + 1, handlers->get_tpr_stack);
439          break;
440      default:
441          abort();
442      }
443  
444      g_free(info);
445  }
446  
447  static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip)
448  {
449      MachineState *ms = MACHINE(qdev_get_machine());
450      CPUState *cs = CPU(cpu);
451      VAPICHandlers *handlers;
452      PatchInfo *info;
453  
454      if (ms->smp.cpus == 1) {
455          handlers = &s->rom_state.up;
456      } else {
457          handlers = &s->rom_state.mp;
458      }
459  
460      info  = g_new(PatchInfo, 1);
461      info->handler = handlers;
462      info->ip = ip;
463  
464      async_safe_run_on_cpu(cs, do_patch_instruction, RUN_ON_CPU_HOST_PTR(info));
465  }
466  
467  void vapic_report_tpr_access(DeviceState *dev, CPUState *cs, target_ulong ip,
468                               TPRAccess access)
469  {
470      VAPICROMState *s = VAPIC(dev);
471      X86CPU *cpu = X86_CPU(cs);
472      CPUX86State *env = &cpu->env;
473  
474      cpu_synchronize_state(cs);
475  
476      if (evaluate_tpr_instruction(s, cpu, &ip, access) < 0) {
477          if (s->state == VAPIC_ACTIVE) {
478              vapic_enable(s, cpu);
479          }
480          return;
481      }
482      if (update_rom_mapping(s, env, ip) < 0) {
483          return;
484      }
485      if (vapic_enable(s, cpu) < 0) {
486          return;
487      }
488      patch_instruction(s, cpu, ip);
489  }
490  
491  typedef struct VAPICEnableTPRReporting {
492      DeviceState *apic;
493      bool enable;
494  } VAPICEnableTPRReporting;
495  
496  static void vapic_do_enable_tpr_reporting(CPUState *cpu, run_on_cpu_data data)
497  {
498      VAPICEnableTPRReporting *info = data.host_ptr;
499      apic_enable_tpr_access_reporting(info->apic, info->enable);
500  }
501  
502  static void vapic_enable_tpr_reporting(bool enable)
503  {
504      VAPICEnableTPRReporting info = {
505          .enable = enable,
506      };
507      CPUState *cs;
508      X86CPU *cpu;
509  
510      CPU_FOREACH(cs) {
511          cpu = X86_CPU(cs);
512          info.apic = cpu->apic_state;
513          run_on_cpu(cs, vapic_do_enable_tpr_reporting, RUN_ON_CPU_HOST_PTR(&info));
514      }
515  }
516  
517  static void vapic_reset(DeviceState *dev)
518  {
519      VAPICROMState *s = VAPIC(dev);
520  
521      s->state = VAPIC_INACTIVE;
522      s->rom_state_paddr = 0;
523      vapic_enable_tpr_reporting(false);
524  }
525  
526  /*
527   * Set the IRQ polling hypercalls to the supported variant:
528   *  - vmcall if using KVM in-kernel irqchip
529   *  - 32-bit VAPIC port write otherwise
530   */
531  static int patch_hypercalls(VAPICROMState *s)
532  {
533      hwaddr rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK;
534      static const uint8_t vmcall_pattern[] = { /* vmcall */
535          0xb8, 0x1, 0, 0, 0, 0xf, 0x1, 0xc1
536      };
537      static const uint8_t outl_pattern[] = { /* nop; outl %eax,0x7e */
538          0xb8, 0x1, 0, 0, 0, 0x90, 0xe7, 0x7e
539      };
540      uint8_t alternates[2];
541      const uint8_t *pattern;
542      const uint8_t *patch;
543      off_t pos;
544      uint8_t *rom;
545  
546      rom = g_malloc(s->rom_size);
547      cpu_physical_memory_read(rom_paddr, rom, s->rom_size);
548  
549      for (pos = 0; pos < s->rom_size - sizeof(vmcall_pattern); pos++) {
550          if (kvm_irqchip_in_kernel()) {
551              pattern = outl_pattern;
552              alternates[0] = outl_pattern[7];
553              alternates[1] = outl_pattern[7];
554              patch = &vmcall_pattern[5];
555          } else {
556              pattern = vmcall_pattern;
557              alternates[0] = vmcall_pattern[7];
558              alternates[1] = 0xd9; /* AMD's VMMCALL */
559              patch = &outl_pattern[5];
560          }
561          if (memcmp(rom + pos, pattern, 7) == 0 &&
562              (rom[pos + 7] == alternates[0] || rom[pos + 7] == alternates[1])) {
563              cpu_physical_memory_write(rom_paddr + pos + 5, patch, 3);
564              /*
565               * Don't flush the tb here. Under ordinary conditions, the patched
566               * calls are miles away from the current IP. Under malicious
567               * conditions, the guest could trick us to crash.
568               */
569          }
570      }
571  
572      g_free(rom);
573      return 0;
574  }
575  
576  /*
577   * For TCG mode or the time KVM honors read-only memory regions, we need to
578   * enable write access to the option ROM so that variables can be updated by
579   * the guest.
580   */
581  static int vapic_map_rom_writable(VAPICROMState *s)
582  {
583      hwaddr rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK;
584      MemoryRegionSection section;
585      MemoryRegion *mr = get_system_memory();
586      size_t rom_size;
587      uint8_t *ram;
588  
589      if (s->rom_mapped_writable) {
590          memory_region_del_subregion(mr, &s->rom);
591          object_unparent(OBJECT(&s->rom));
592      }
593  
594      /* grab RAM memory region (region @rom_paddr may still be pc.rom) */
595      section = memory_region_find(mr, 0, 1);
596  
597      /* read ROM size from RAM region */
598      if (rom_paddr + 2 >= memory_region_size(section.mr)) {
599          return -1;
600      }
601      ram = memory_region_get_ram_ptr(section.mr);
602      rom_size = ram[rom_paddr + 2] * ROM_BLOCK_SIZE;
603      if (rom_size == 0) {
604          return -1;
605      }
606      s->rom_size = rom_size;
607  
608      /* We need to round to avoid creating subpages
609       * from which we cannot run code. */
610      rom_size += rom_paddr & ~TARGET_PAGE_MASK;
611      rom_paddr &= TARGET_PAGE_MASK;
612      rom_size = TARGET_PAGE_ALIGN(rom_size);
613  
614      memory_region_init_alias(&s->rom, OBJECT(s), "kvmvapic-rom", section.mr,
615                               rom_paddr, rom_size);
616      memory_region_add_subregion_overlap(mr, rom_paddr, &s->rom, 1000);
617      s->rom_mapped_writable = true;
618      memory_region_unref(section.mr);
619  
620      return 0;
621  }
622  
623  static int vapic_prepare(VAPICROMState *s)
624  {
625      if (vapic_map_rom_writable(s) < 0) {
626          return -1;
627      }
628  
629      if (patch_hypercalls(s) < 0) {
630          return -1;
631      }
632  
633      vapic_enable_tpr_reporting(true);
634  
635      return 0;
636  }
637  
638  static void vapic_write(void *opaque, hwaddr addr, uint64_t data,
639                          unsigned int size)
640  {
641      VAPICROMState *s = opaque;
642      X86CPU *cpu;
643      CPUX86State *env;
644      hwaddr rom_paddr;
645  
646      if (!current_cpu) {
647          return;
648      }
649  
650      cpu_synchronize_state(current_cpu);
651      cpu = X86_CPU(current_cpu);
652      env = &cpu->env;
653  
654      /*
655       * The VAPIC supports two PIO-based hypercalls, both via port 0x7E.
656       *  o 16-bit write access:
657       *    Reports the option ROM initialization to the hypervisor. Written
658       *    value is the offset of the state structure in the ROM.
659       *  o 8-bit write access:
660       *    Reactivates the VAPIC after a guest hibernation, i.e. after the
661       *    option ROM content has been re-initialized by a guest power cycle.
662       *  o 32-bit write access:
663       *    Poll for pending IRQs, considering the current VAPIC state.
664       */
665      switch (size) {
666      case 2:
667          if (s->state == VAPIC_INACTIVE) {
668              rom_paddr = (env->segs[R_CS].base + env->eip) & ROM_BLOCK_MASK;
669              s->rom_state_paddr = rom_paddr + data;
670  
671              s->state = VAPIC_STANDBY;
672          }
673          if (vapic_prepare(s) < 0) {
674              s->state = VAPIC_INACTIVE;
675              s->rom_state_paddr = 0;
676              break;
677          }
678          break;
679      case 1:
680          if (kvm_enabled()) {
681              /*
682               * Disable triggering instruction in ROM by writing a NOP.
683               *
684               * We cannot do this in TCG mode as the reported IP is not
685               * accurate.
686               */
687              pause_all_vcpus();
688              patch_byte(cpu, env->eip - 2, 0x66);
689              patch_byte(cpu, env->eip - 1, 0x90);
690              resume_all_vcpus();
691          }
692  
693          if (s->state == VAPIC_ACTIVE) {
694              break;
695          }
696          if (update_rom_mapping(s, env, env->eip) < 0) {
697              break;
698          }
699          if (find_real_tpr_addr(s, env) < 0) {
700              break;
701          }
702          vapic_enable(s, cpu);
703          break;
704      default:
705      case 4:
706          if (!kvm_irqchip_in_kernel()) {
707              apic_poll_irq(cpu->apic_state);
708          }
709          break;
710      }
711  }
712  
713  static uint64_t vapic_read(void *opaque, hwaddr addr, unsigned size)
714  {
715      return 0xffffffff;
716  }
717  
718  static const MemoryRegionOps vapic_ops = {
719      .write = vapic_write,
720      .read = vapic_read,
721      .endianness = DEVICE_NATIVE_ENDIAN,
722  };
723  
724  static void vapic_realize(DeviceState *dev, Error **errp)
725  {
726      SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
727      VAPICROMState *s = VAPIC(dev);
728  
729      memory_region_init_io(&s->io, OBJECT(s), &vapic_ops, s, "kvmvapic", 2);
730      memory_region_add_subregion(get_system_io(), VAPIC_IO_PORT, &s->io);
731      sysbus_init_ioports(sbd, VAPIC_IO_PORT, 2);
732  
733      option_rom[nb_option_roms].name = "kvmvapic.bin";
734      option_rom[nb_option_roms].bootindex = -1;
735      nb_option_roms++;
736  }
737  
738  static void do_vapic_enable(CPUState *cs, run_on_cpu_data data)
739  {
740      VAPICROMState *s = data.host_ptr;
741      X86CPU *cpu = X86_CPU(cs);
742  
743      static const uint8_t enabled = 1;
744      cpu_physical_memory_write(s->vapic_paddr + offsetof(VAPICState, enabled),
745                                &enabled, sizeof(enabled));
746      apic_enable_vapic(cpu->apic_state, s->vapic_paddr);
747      s->state = VAPIC_ACTIVE;
748  }
749  
750  static void vapic_vm_state_change(void *opaque, bool running, RunState state)
751  {
752      MachineState *ms = MACHINE(qdev_get_machine());
753      VAPICROMState *s = opaque;
754      uint8_t *zero;
755  
756      if (!running) {
757          return;
758      }
759  
760      if (s->state == VAPIC_ACTIVE) {
761          if (ms->smp.cpus == 1) {
762              run_on_cpu(first_cpu, do_vapic_enable, RUN_ON_CPU_HOST_PTR(s));
763          } else {
764              zero = g_malloc0(s->rom_state.vapic_size);
765              cpu_physical_memory_write(s->vapic_paddr, zero,
766                                        s->rom_state.vapic_size);
767              g_free(zero);
768          }
769      }
770  
771      qemu_del_vm_change_state_handler(s->vmsentry);
772      s->vmsentry = NULL;
773  }
774  
775  static int vapic_post_load(void *opaque, int version_id)
776  {
777      VAPICROMState *s = opaque;
778  
779      /*
780       * The old implementation of qemu-kvm did not provide the state
781       * VAPIC_STANDBY. Reconstruct it.
782       */
783      if (s->state == VAPIC_INACTIVE && s->rom_state_paddr != 0) {
784          s->state = VAPIC_STANDBY;
785      }
786  
787      if (s->state != VAPIC_INACTIVE) {
788          if (vapic_prepare(s) < 0) {
789              return -1;
790          }
791      }
792  
793      if (!s->vmsentry) {
794          s->vmsentry =
795              qemu_add_vm_change_state_handler(vapic_vm_state_change, s);
796      }
797      return 0;
798  }
799  
800  static const VMStateDescription vmstate_handlers = {
801      .name = "kvmvapic-handlers",
802      .version_id = 1,
803      .minimum_version_id = 1,
804      .fields = (const VMStateField[]) {
805          VMSTATE_UINT32(set_tpr, VAPICHandlers),
806          VMSTATE_UINT32(set_tpr_eax, VAPICHandlers),
807          VMSTATE_UINT32_ARRAY(get_tpr, VAPICHandlers, 8),
808          VMSTATE_UINT32(get_tpr_stack, VAPICHandlers),
809          VMSTATE_END_OF_LIST()
810      }
811  };
812  
813  static const VMStateDescription vmstate_guest_rom = {
814      .name = "kvmvapic-guest-rom",
815      .version_id = 1,
816      .minimum_version_id = 1,
817      .fields = (const VMStateField[]) {
818          VMSTATE_UNUSED(8),     /* signature */
819          VMSTATE_UINT32(vaddr, GuestROMState),
820          VMSTATE_UINT32(fixup_start, GuestROMState),
821          VMSTATE_UINT32(fixup_end, GuestROMState),
822          VMSTATE_UINT32(vapic_vaddr, GuestROMState),
823          VMSTATE_UINT32(vapic_size, GuestROMState),
824          VMSTATE_UINT32(vcpu_shift, GuestROMState),
825          VMSTATE_UINT32(real_tpr_addr, GuestROMState),
826          VMSTATE_STRUCT(up, GuestROMState, 0, vmstate_handlers, VAPICHandlers),
827          VMSTATE_STRUCT(mp, GuestROMState, 0, vmstate_handlers, VAPICHandlers),
828          VMSTATE_END_OF_LIST()
829      }
830  };
831  
832  static const VMStateDescription vmstate_vapic = {
833      .name = "kvm-tpr-opt",      /* compatible with qemu-kvm VAPIC */
834      .version_id = 1,
835      .minimum_version_id = 1,
836      .post_load = vapic_post_load,
837      .fields = (const VMStateField[]) {
838          VMSTATE_STRUCT(rom_state, VAPICROMState, 0, vmstate_guest_rom,
839                         GuestROMState),
840          VMSTATE_UINT32(state, VAPICROMState),
841          VMSTATE_UINT32(real_tpr_addr, VAPICROMState),
842          VMSTATE_UINT32(rom_state_vaddr, VAPICROMState),
843          VMSTATE_UINT32(vapic_paddr, VAPICROMState),
844          VMSTATE_UINT32(rom_state_paddr, VAPICROMState),
845          VMSTATE_END_OF_LIST()
846      }
847  };
848  
849  static void vapic_class_init(ObjectClass *klass, void *data)
850  {
851      DeviceClass *dc = DEVICE_CLASS(klass);
852  
853      dc->reset   = vapic_reset;
854      dc->vmsd    = &vmstate_vapic;
855      dc->realize = vapic_realize;
856  }
857  
858  static const TypeInfo vapic_type = {
859      .name          = TYPE_VAPIC,
860      .parent        = TYPE_SYS_BUS_DEVICE,
861      .instance_size = sizeof(VAPICROMState),
862      .class_init    = vapic_class_init,
863  };
864  
865  static void vapic_register(void)
866  {
867      type_register_static(&vapic_type);
868  }
869  
870  type_init(vapic_register);
871